which of the following elements has the smallest ionization energy? choose 1 answer: a b b c c o

Answer:

A. B

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period from left - to - right.

Step2: Locate elements in periodic table

B (boron), C (carbon), and O (oxygen) are in the second period. B is the left - most among them.

Step3: Determine the answer

Since B is the left - most, it has the smallest ionization energy among the three.